2h frost - strength vs. critical strike

With 5.4 we have had several changes that significantly reduced the value of additional haste past ~5-7k in heroic gear. Mastery is somewhat limited in value for 2h due to its attack priorities. That places critical strike as the most valuable secondary, which despite being devalued by KM, I can accept. What seems strange to me is the jump in crits value above strength (gem wise). Until late 5.3 I had never run across any simulation which placed critical strike above strength for 2h frost (again, gem wise). Now with the new simulations in 5.4 crit is suddenly well above strength in most situations, which would seem to indicate a reduced scaling effect of strength. Granted obliterate and frost strike are weapon damage based and not AP based, making strength's contribution limited to the AP component of weapon damage scaling, but I do have a hard time believing an item level jump from ~543 to ~574 would see such a large increase in crit scaling and/or a decrease in strength scaling. I have yet to see any skilled DK gemming strength and I haven't had an opportunity to compare strenght gemming to crit gemming in a raid in weeks (offtanking at the moment), but I find myself questioning the accuracy of our simulations.

This is just the way scaling works. Once we've reached a certain amount of base stats (STR) which increase our damage linearly, the stats that increase our damage based on percentages (Haste/Crit/Mastery - In this case Crit) win out.

I dont really get it either. At the moment I'm using str-crit gems in my yellow slots but I cant bring myself to gem crit. And sites like akmrobot are saying I should gem expertise-crit that just seems silly to me. 160str is 320ap that seems like it should be better than 300 crit to me. I've even seen guys geming full yellow gems in red slots. It just looks and feels wrong.

I've seen this question pop up a few times so i'll make this post a thought experiment on the scaling of secondaries vs the scaling of strength. Note that the formulas I use may not be entirely accurate. Raidbuffs like 10% attack power, 5% strength and other percentage increases make this more complicated so for this example I will ignore them.

This ends up being a roughly 10% increase in damage for a 10% increase in attack power.

Assuming no buffs like I mentioned above, in order to get a 10% increase, it takes 5,000 strength to achieve this.
What about if you used mastery? At level 90 for every 300 points of mastery, you gain 1% frost damage so at 100,000 AP, it would take 3,000 mastery to gain the same effect as 5000 strength. Mastery is clearly a winner here.

Again this is roughly a 10% increase in damage for 10% increase in attack power and it takes a total of 1,000 strength to get this.
However this time to get 10% increase by using mastery, it still takes 3,000 rating.

This may seem obvious, at lower gear levels, percentage based increases like mastery are less effective than raw increasing attributes but this needs to be applied to crit as well!

Think about crit like this, Since attacks crit for double, at 100% crit you are essentially doing double damage compared to if you are not able to crit at all. At 50% crit, you are doing 100% more damage, 50% of the time, for 50% increase in damage.

The key here is to think of crit as a percentage increase just as you would mastery. Haste? Haste is interesting. On one hand you can have too much because at some point, you are unable to spend all your resources in an allotment of time. On the other hand, having lots at higher gear levels "should" be good right? The difference between haste and mastery/crit/strength is that having more haste does not increase the damage of one global for us so comparing them in this way would be...difficult.

But what I can tell you about haste is that using PL has drastic impacts on the value of haste. Sim it for yourself and see the difference, 2 runes every 30 seconds is quite big in the long run!